JP2000272776A - Carrying device of matter to be printed and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically control a series of processes of pressure reduction, separation, pressure contact and pressurization of two rollers by providing an object sensor for detecting matter to be printed that is carried through two juxtaposed rollers, and controlling the approaching and separating movements of both the rollers on the basis of the detection signal. SOLUTION: A heat roller B1 is supported in a fixed position of a chassis B5, and a pressure roller B2 is supported in such a manner as to be movable along a circular groove C4 through a gear train by the operation of a stepping motor M1 or capable of approaching to and separating from the heat roller B1. When a sheet passage sensor detect a jam, the stepping motor M1 is rotated by a designated number of times to space the heat roller B1 from the pressure roller B2. When the jam is solved, and the sheet passage sensor detects the printable state, the stepping motor M1 is reversely rotated, and the pressure roller B2 is moved until a pressure sensor detects a proper pressure, and pressed onto the heat roller B1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transport device for an image forming apparatus such as a copying machine and a printer, and more particularly to a control system for easily removing paper from a paper transport path and an operation mechanism suitable for automatic control thereof. Things.

[0002]

2. Description of the Related Art Generally, in an image forming apparatus such as a copying machine or a printer, a plurality of transfer devices having two transfer rollers arranged side by side are provided on a transfer path in order to correctly transfer a printing material such as copy paper to a path. , And presence detection and proximity sensors are installed at each site. Conventional paper path sensors or switches are used to maintain the trajectory of document and paper positions within the machine, and often all functions of the machine are managed by a controller, such as a programmable microprocessor.

In a typical electrophotographic electrostatic copying machine, copy paper is positioned and aligned by a plurality of transport rollers from a paper feeder and automatically transported to an image transfer unit. In the image transfer section, the copy sheet contacts the photoconductive drum or the photoconductive belt on which the toner powder image is formed, and moves while being aligned in terms of position and time. As a result, the toner powder image is transferred to copy paper.

Next, the copy sheet to which the toner powder image has been transferred is transported to a fixing device via a transport roller. The fixing device includes a heating roller and a pressure roller, and the heating roller melts the transferred toner image, and the pressure roller generates a pressure necessary to fix the toner powder image to copy paper. The copy sheet passes through the pressure contact surface between the heating roller and the pressure roller, and the toner image adhered to the copy sheet is melt-pressed by the heat treatment and the pressure treatment of the fixing device, and is permanently fixed on the copy sheet.

[0005] Further, the copy paper on which the toner powder image has been fixed is bidirectionally bent by a plurality of transport rollers and then sent out of the machine in order to remove curls and wrinkles taken into the copy paper. In this way, the copy paper is flowed to the paper discharge support by a number of transport rollers inside the machine. The photoconductive drum or photoconductive belt in the transfer section, the heating roller and the pressure roller of the fixing device also function as transport rollers.

In electrostatic copying machines such as facsimile machines and printers other than the electrophotographic system, a plurality of positioning / conveying rollers feed paper from a paper feeder such as a paper cassette or a manual tray into a main body of the apparatus. After the image is formed, the image is discharged outside the apparatus.

In the case where a printing material such as copy paper is pinched and jammed by such a transport roller and a paper jam occurs, in a certain copying machine, an electronic control system is installed along the paper transport path. The occurrence of a paper jam is sensed by the paper path sensor, the operation of the machine is stopped, and the occurrence and location of the paper jam and the method of removing the paper are displayed to the operator on the operation panel. At that time, in order to resume printing, the operator needs to open the access door and pull the drawer to open the apparatus to remove the jammed paper.

However, in order to improve the maintenance of the paper, at least one of the two rollers is made of an elastic material such as rubber with little slip, and the paper is rolled without rotating the roller. It cannot be pulled out by sliding on the outer surface. In addition, since other rollers and drive motors are connected to the transport rollers by gears and the like, the resistance is large.In particular, the fixing device is always fixed between the pressure roller and the heating roller to fix the toner on the copy paper. When the copy paper is jammed inside the printer, a considerable amount of force is required to remove the copy paper. The paper may be damaged. If the paper is damaged, fragments of the paper are left behind in the apparatus, making it difficult to remove them. In some cases, the removal means is lost, and a handling company is called out, or the worst situation occurs in which the inside of the apparatus is damaged and repaired. In addition, there is a concern that the operator may be burned or entangled.

Conventionally, the following means have been provided as means for solving such a problem. That is, means for releasing the connection of the gear that transmits power to the transport roller and reducing the resistance to the roller, means for releasing the pressure between the rollers, and means for further separating the rollers after the pressure is released, There are means for manually rotating each roller, etc., and most of them are based on a combination of these. Regarding the fixing device, a solution for releasing the pressure between the rollers by a release lever and a mechanism connected to the release device, and pulling out the roller after the separation is disclosed in Japanese Utility Model Laid-Open No. 5-084967,
No. 278669, JP-A-9-034299 and JP-A-10-207272.

Further, in order to prevent a situation in which the release lever may be forgotten to be returned in the disclosed invention or the disclosed invention, even if the release lever is forgotten to be returned, the mechanism for returning the lever in conjunction with the operation of the device and returning the pressure is restored. Japanese Patent Application Laid-Open No. 9-212030 discloses an invention adopting the method described in Japanese Patent Application Laid-Open No. 9-212030, however, it still fails to eliminate the troublesomeness that the operator needs to operate the release lever before removing the jammed paper. For operators who are not used to handling the inside of the device, even after the release lever is painted in a conspicuous color after opening the device,
It takes time to find the release lever and to determine in which direction to turn it, and the workability is impaired. In addition, any of the above-described mechanisms of the invention or device is not suitable for operation by a rotary motor because it is premised that an operator performs a lever operation. Therefore, it is not suitable for controlling the pressure deviation of the roller by the electronic control system described above. Therefore, there are still many problems in the prior art.

[00011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior art, and has been made in view of the above-mentioned problems. It is an object of the present invention to provide a transfer device or an image processing device capable of automatically controlling a series of processes such as pressure and pressure.

It is another object of the present invention to improve the workability of the operator and to speed up, smoothen, and improve the safety of the printing material removing operation. It is still another object of the present invention to provide an operation mechanism optimal for operating the moving amount of a conveying roller such as a pressure roller with high efficiency and high accuracy in providing the above-described apparatus.

[00013]

According to a first aspect of the present invention, there is provided a driving apparatus comprising: a driving source; and two rollers arranged in parallel including at least one roller receiving a driving force from the driving source. An object sensor for detecting an object to be printed that is conveyed between the two rollers, and control means for controlling a pressure separation between the two rollers based on a signal transmitted from the object sensor. It is a printed matter transport device.

Therefore, according to the printing medium transporting apparatus of the first invention of the present application, first, when an object sensor such as a presence sensor or a proximity sensor detects an error such as a paper jam, and the apparatus stops because printing is disabled, Since the contact pressure between the two rollers is automatically released so as to be linked with each other, there is an advantage that there is no unnecessary resistance when an operator removes the substrate, and the substrate can be easily removed. Further, since both rollers can be completely separated from each other, there is an advantage that the removal of the printing medium is facilitated. Further, after the operator removes the printing material, the object sensor detects that an error such as a paper jam has been cleared, and that there is no new obstacle such as the operator's hand. Since the state is restored, there is an advantage in work efficiency that the printer is automatically restored to the printable state, and a safety advantage that there is no need to approach and press both rollers as long as there is an obstacle between the rollers. There is.

The second invention of the present application comprises a driving source,
Two rollers arranged side by side including at least one roller that receives a driving force from the driving source, and an object sensor that detects a printing target that is conveyed between the two rollers,
A pressure sensor for detecting the pressure of the pressure contact of the two rollers,
Control means for controlling a pressure contact divergence between the two rollers and a pressure of the pressure contact based on signals transmitted from the two sensors.

Therefore, the printing medium transporting apparatus of the second invention of the present application has the function of monitoring the pressure between the two rollers by means of a pressure sensor in addition to the function of the first invention of the present application, so that it is necessary to transport the printing medium. It has a function of controlling the pressure necessary for the secondary role of the transport device, such as applying an appropriate pressure or pressurizing the print medium. Therefore, according to the printing medium conveying apparatus of the second invention of the present application, there is an advantage that the necessary pressure is defined according to the function of the conveying apparatus and the thickness of the printing medium, and unnecessary pressure is not applied to the printing medium. .

According to a third invention of the present application, in the printing medium transport apparatus of the first invention of the present application or the second invention of the present application, the control means for controlling the pressure separation between the two rollers or the pressure of the pressure contact is provided by a stepping motor. A movable supporting means for supporting at least both rollers so as to be separated from each other by pressure, and a power transmitting means for transmitting the rotational power of the stepping motor to the movable supporting means.

Therefore, according to the printing medium transporting apparatus of the third invention of the present application, since the pressure contact divergence of both rollers is operated by the stepping motor, there is an advantage that the relative position or pressure of both rollers can be precisely operated.

According to a fourth invention of the present application, in the printing medium transporting apparatus of the third invention of the present application, the power transmission means is constituted by a gear train, and the movable support means comprises a gear mounted on an end of a roller shaft. And a gear receiving gear meshing with the gear receiving gear, and a pitch surface of the gear receiving is formed as a part of a coaxial cylinder with a gear that is in direct contact conduction with a gear mounted on the roller shaft end.

Therefore, according to the printing medium conveying apparatus of the fourth invention of the present application, the joint of the pitch surfaces of the gears is always maintained before and after the series of operations (the distance between the axes of the gears does not change). No unnecessary force is applied to disengage the rollers from pressure contact, and the gear transmission efficiency is maintained at a high level to realize smooth movement.

According to a fifth invention of the present application, in the printing medium transporting apparatus of the third invention of the present application, the power transmission means is constituted by a gear train and a winding conduction member, and the movable support means is provided at an end of the roller shaft. It is composed of a gear to be mounted and a gear receiver meshing with the gear, and the winding conductive member has a winding part of a gear mounted on the roller shaft end and a winding part of one of the gear trains. And a pitch surface of the gear receiver is formed as a part of a coaxial cylinder with the one gear. The winding portion is a belt wheel for belt conduction, a groove wheel for rope conduction, and a sprocket for chain conduction.

Therefore, according to the printing medium transporting apparatus of the fifth invention of the present application, since the power of the stepping motor is transmitted by the winding conductive member such as a belt, a rope, and a chain, the power can be transmitted from a distant place. There is an advantage that the operation is quiet, the shock is absorbed, and the machine is not forced. Also, it can be manufactured at low cost. It is preferable to use a belt or a rope to further reduce noise. It is preferable to use a rope in order to make it cheaper. With belt or rope conduction, the direction of conduction can be changed. In order to prevent slippage and keep the speed ratio constant, it is preferable to use a chain. According to the chain conduction, the speed ratio is reliably maintained, and high-speed and strong conduction is possible.

According to a sixth aspect of the present invention, in the printing medium conveying apparatus according to the third aspect of the present invention, the power transmission means is constituted by a gear train, and the movable support means is constituted by a rack mounted on a roller shaft end. The rack is meshed with one of the gear trains.

Therefore, according to the printing material conveying apparatus of the sixth aspect of the present invention, the rollers supported by the rack move linearly and do not move in unnecessary directions to separate the rollers by pressing, so that the energy of the power source is Has the advantage of less waste. In addition, there is no need for gear bearings with teeth,
There is an advantage that the device as a whole is easy to manufacture and finished at low cost.

According to a seventh aspect of the present invention, in the printing medium transporting apparatus according to the fourth, fifth or sixth aspect of the present invention, the movable supporting means is provided with a support by a spring.

Therefore, according to the printing medium transporting apparatus of the seventh application of the present invention, if the transmission of the power is stopped, the roller which is movably supported by the restoring force of the spring returns to the predetermined position, so that it is unnecessary to use the power accordingly. There is an advantage that. Further, there is an advantage that a predetermined pressure is generated between the pressure roller and the heating roller due to the stress of the spring without installing a pressure sensor.
Further, in the case of the above-described device in which the pressure between the two rollers is defined by the stepping motor, the accuracy of the stepping motor affects the accuracy of the pressure between the two rollers. Is not necessarily required. In addition, as a result of reducing the load on the stepping motor by burdening the gravity applied to the pressure roller and the like,
The movement of the whole mechanism is also performed smoothly.

According to an eighth aspect of the present invention, there is provided a central control device, at least one or more of the printed matter transporting devices according to any one of the first to thirteenth aspects, and transported by the printed matter transporting device. An image forming apparatus, comprising: an image forming unit that forms an image on a print target according to image information.

Therefore, according to the printing medium conveying apparatus of the eighth invention of the present application, when the object sensor detects an error such as a paper jam or the like and the apparatus is stopped due to the printing failure, the central control device is controlled by the conveying apparatus among the plurality of conveying apparatuses. It is possible to release the contact pressure of both rollers only to the transport device where printed matter is stagnated, and to issue a command to completely separate both rollers if necessary.Therefore, a transport device that does not require removal of jammed paper etc. There is an advantage that it is not necessary to operate the printer unnecessarily, and it is easy for the operator to find out the location of the printing material to be removed. Also, after the operator removes the printing material, the central control unit restores the transport device to a printable state and starts reprinting of the error page, or changes the printable state through the operation panel without reprinting. Since it is possible to notify the operator and wait, it is advantageous to further reduce the work load of the operator.

[0029]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an image forming apparatus according to an embodiment of the present invention.

FIG. 1 is a flowchart illustrating the operation of the printing medium transporting apparatus and the image forming apparatus according to an embodiment of the present invention, taking a fixing device as an example. When the apparatus detects a paper jam with the paper path sensor (A1), the apparatus automatically rotates the stepping motor a specified number of times to extend the interval between the heating roller and the pressure roller (A2). When the copy paper is removed and a printable state is detected by the paper path sensor (A
3) The device automatically rotates the stepping motor in the opposite direction to A2, and repeats the rotation until the pressure sensor detects an appropriate pressure (A4, A5).

When the value of the pressure sensor reaches a value necessary for fixing (A6), the rotation of the stepping motor is stopped (A6).
6). Further, the operator is notified through the operation panel that printing is possible, or reprinting is started and a message to that effect is displayed on the operation panel (A7).

Next, an embodiment of the present invention will be described with reference to the accompanying drawings, taking a fixing device as an example. FIG. 2 is a left side view (a) and a front view (b) of a conventional fixing device. B1 is a heating roller, B2 is a pressing roller, and B3 and B4 are fixtures for fixing the axes of the heating roller B1 and the pressing roller B2, respectively. B5 indicates a chassis (housing) to which each roller is fixed by a fixing bracket. P1 is a portion to be improved of the fixing device of the present invention.

Embodiment 1 FIG. 3 shows a main configuration of Embodiment 1 of the present invention. FIGS. 4 and 5 are schematic diagrams of a fixing device to which this is applied.
FIG. 4 shows a pressure contact state between the heating roller and the pressure roller.
Indicates a deviation state. 4A and 5A are left side views, respectively. 4B and 5B are front views. FIG. 6 is a sectional view taken along line II of FIG.

M1 is a stepping motor, and C1 is a gear mounted on the shaft of the stepping motor M1. C2 is a gear meshing with the gear C1, and C3 is a central axis of the gear C2. C4 is a gear that meshes with the gear C2, and is attached to both ends of the central axis of the pressure roller B2. C5 is a groove through which the central axis of the gear C4 passes, and C6 is a gear receiver provided inside the groove, in which teeth are arranged on an arc concentric with the gear C4. Referring to the sectional view of FIG. 6, the gear C4 is composed of coaxial gears C41 and C42, and the gear C41 meshes with the gear C2 at P3, and the gear C42
Has a structure meshing with the gear receiver C6 at P2. A similar configuration may be adopted on the right side surface, but a configuration in which the stepping motor M1 is omitted and the left and right gears C2 are connected by a shaft is adopted. This requires only one stepping motor M1 and mechanically connects the left and right mechanisms, so that the rollers can be kept horizontal during operation.

Referring to FIG. 4A, the stepping motor M
1 rotates clockwise, the gear C4 moves in the direction of the arrow shown in the figure.
Moves, and the pressure roller B2 approaches the heating roller B1. Further rotation produces the required pressure. As shown in FIG. 5A, when the stepping motor M1 rotates counterclockwise, the gear C4 moves in the direction of the arrow shown in FIG.
The pressure between 2 and the heating roller B1 disappears. Further rotation causes a necessary gap between the two rollers.

Second Embodiment Next, a printing medium transporting apparatus according to another embodiment of the present invention will be described with reference to FIG. As shown in FIG.
, So that the central axis of the pressure roller B2 is rotatably supported. In the case of the fixing device shown in FIG. 7, since the spring D1 is attached so that the pressing roller B2 is pressed against the heating roller B1 by the contracting force of the spring itself, the pressing roller B2 is rotated by the rotation of the stepping motor M1. And then the paper jam is removed and the pressure roller B
When the pressure roller B2 is returned to the pressed state, the pressure roller B2 is naturally moved to the heating roller B1 side by the contraction force of the spring D1 instead of the rotation drive of the stepping motor M1. After contacting the heating roller B1, a constant pressure is created between the rollers by the elastic energy still remaining of the spring. In this case, the pressure required for fixing the toner powder image can be secured without installing a pressure sensor (not shown). Also, a highly accurate stepping motor is not required.

Third Embodiment Next, another embodiment of the present invention will be described with reference to FIG. FIG. 8 is a schematic diagram of a fixing device to which the present invention is applied, and FIG.
(B) is a front view.

The printing medium transporting apparatus according to the present embodiment employs a configuration in which power is transmitted by winding conduction. E2 is a belt, and E1 and E4 are belt wheels. The belt E2 is wound around the belt wheel E1 and the belt wheel E4. A tooth row is provided on the inner side of the belt E2 and on the outer periphery of the belt wheel E1 and the belt wheel E4 in order to eliminate slippage of the belt. E
3 is a gear receiver for receiving the gear C42. The gear receiver E3 has teeth arranged in an arc shape concentric with the belt wheel E1.
M1 indicates a stepping motor.

Referring to FIG. 8, the stepping motor M
It can be seen that the rotation of 1 causes the pressure roller B2 to move up and down along the arc of the gear receiver E3. For example, when the stepping motor M1 is rotated clockwise as viewed in FIG. 8A, the pressure roller B2 rises and approaches the heating roller.

Fourth Embodiment Next, a description will be given of a printing medium transporting apparatus according to another embodiment of the present invention with reference to FIG. FIG. 9 is a schematic diagram of a fixing device to which the present invention is applied, and FIG.
(B) is a front view.

F1 is a support for supporting the shaft of the pressure roller B2. F2 is a rack provided on a part of the support F1, and meshes with the gear C2. F3 is a fulcrum roller attached to both ends of the support F1, and is a guide rail F4.
And supports the support F1 movably in a linear direction toward the heating roller. F5 is a tension spring attached to the shaft of the pressure roller B2, and is fixed to the chassis B5 in such a manner that the pressure roller is suspended from above so that the pressure roller is pressed against the heating roller by the contraction force. . However, a compression spring attached so as to push up from below may be used, and the effect of the present invention is not changed. The spring need not be a coil spring as shown in the figure, but may be a leaf spring, a laminated leaf spring, a U-shaped spring, or the like. The right side of the apparatus may have the same configuration as the left side, but may have a configuration in which the stepping motor M1 is omitted and the gear C2 is connected by a shaft.

According to the fourth embodiment, since the direction of expansion and contraction of the spring F5, the direction of movement of the support F1 and the direction of gravity are on the same line, the expansion and contraction force of the spring F5 and the gravitational force of the pressure roller B2 and the like always remain. A load is applied in the moving direction of the pressure roller B2, and a smooth movement is exhibited. This is because no vertical reaction force is generated at the fulcrum roller F3 which causes friction or at the mesh point between the rack F2 and the gear C2.

[0043]

As described above, the present invention enables the automatic control of the pressure and the pressure contact deviation of the two rollers of the printing medium transporting apparatus, and eliminates the pressure contact pressure recovery and the pressure recovery work of the roller which is conventionally required by the operator. It saves time and effort without adding any trouble to the operator, and greatly improves the workability of the image forming apparatus by shortening the time from when a printing error occurs until printing becomes possible. The effect is obtained.

Also, by eliminating the dangerous work of the operator, the effect of preventing the operator from being injured, such as burning or pinching, can be obtained.

[Brief description of the drawings]

FIG. 1 is a flowchart according to the present invention.

FIG. 2 is a left side view (a) and a front view (b) of a conventional fixing device.

FIG. 3 is a schematic diagram showing a main configuration of the first embodiment of the present invention.

FIG. 4 is a left side view (a) and a front view (b) showing a pressed state of the fixing device according to the first embodiment of the present invention.

FIGS. 5A and 5B are a left side view and a front view showing a separated state of the fixing device according to the first embodiment of the present invention. FIGS.

FIG. 6 is a sectional view taken along the line II of FIG. 5;

FIG. 7 is a schematic diagram showing a main configuration of a second embodiment of the present invention.

FIG. 8 is a left side view (a) and a front view (b) of a fixing device according to a third embodiment of the present invention.

FIG. 9 is a left side view (a) and a front view (b) of a fixing device according to a fourth embodiment of the present invention.

[Explanation of symbols]

 B1 Heating roller B2 Pressure roller B3 Fixture of pressure roller B5 Chassis C1 Gear attached to stepping motor M1 Gear C2 Gear C3 Center shaft C4 Gear attached to pressure roller C5 Groove C6 Gear receiver D1 Spring E1 Belt wheel E2 Belt E3 Gear bearing E4 Belt wheel F1 Support for supporting the shaft of the pressure roller B2 F2 Rack F3 Support roller F4 Guide rail F5 Tension spring

Claims (8)

[Claims] 1. A driving source, two rollers arranged side by side including at least one roller receiving a driving force from the driving source, and an object for detecting an object to be printed passing between the two rollers An apparatus for transporting a printed material, comprising: a sensor; and control means for controlling a pressure separation between the two rollers based on a signal transmitted from the object sensor. 2. A driving source, two rollers arranged side by side including at least one roller receiving a driving force from the driving source, and an object for detecting an object to be printed which is conveyed between the two rollers. A sensor, a pressure sensor for detecting the pressure of the pressure contact point of the both rollers, and control means for controlling the pressure contact divergence of the two rollers and the pressure of the pressure contact based on signals transmitted from the two sensors. Printed object transport device. 3. The control means for controlling the pressure between the two rollers and the pressure contact and separation between the two rollers includes a stepping motor, a movable supporting means for supporting at least the two rollers so as to be able to separate from the pressure, and the rotation power of the stepping motor. 3. The printing medium transport apparatus according to claim 1, further comprising a power transmission unit that transmits the power to the movable support unit. 4. The power transmission means is constituted by a gear train,
The movable support means includes a gear mounted on the roller shaft end and a gear receiver meshed with the gear, and a pitch surface of the gear receiver is a gear which directly contacts and conducts with a gear mounted on the roller shaft end. 4. The apparatus according to claim 3, wherein the apparatus is a part of a coaxial cylinder. 5. The power transmission means comprises a gear train and a winding transmission member, and the movable support means comprises a gear mounted on an end of a roller shaft, and a gear receiver meshing with the gear.
The winding conductive member is wound around a winding portion of a gear mounted on the roller shaft end and a winding portion of one of the gear trains, and a pitch surface of the gear receiver is coaxial with the one gear. 5. The apparatus according to claim 4, wherein the apparatus is a part of a cylinder. 6. The power transmission means is constituted by a gear train,
5. The apparatus according to claim 4, wherein said movable support means is constituted by a rack mounted on a roller shaft end, and said rack is meshed with one of said gear trains. 7. The apparatus according to claim 4, wherein a spring support is added to the movable support means. 8. A central control device, at least one or more of the printing material transporting devices according to claim 1, and image information on a printing material transported by the printing material transporting device. An image forming apparatus, comprising: an image forming unit that forms an image according to the image forming apparatus.